DE 41 12 904 A1 describes a drive torque distribution control device for vehicles, which device has a clutch for varying the torque distribution between first and second drive wheels. The clutch is controlled by means of a control signal which is determined on the basis of the measurement values of an acceleration position sensor and of a lateral acceleration sensor. A disadvantage of said solution is the limited accuracy with which the respective driving situation can be determined. The torques actually acting on the wheels are not determined in said solution.
Various further solutions for measuring other variables are known, each with the aim of determining the torque distribution.
In this connection, DE 689 28 004 T2 describes an arrangement for controlling the force transmission of a four-wheel drive vehicle, in which the variation of the drive torque distribution is selected inter alia also as a function of the present steer angle, the throttle pedal position, the engine power and the braking force.
In DE 40 31 890 A1, it is proposed that the difference in the rotational speeds of the front and rear wheels be determined. It is known from DE 41 33 060 A1 to additionally determine the wind yaw moment generated by side wind. All of said solutions have in common that the determination of the torque distribution takes place only indirectly, such that the level of accuracy which is obtained is unsatisfactory in many driving situations.
From DE 195 14 093 B4, it is known to determine the torsion in the wheel drive axles of a vehicle by means of speed sensors at the wheel driveshafts. For this purpose, it is necessary to determine further characteristic variables such as the rotational speed of the drive unit and the degree of throttle flap opening. An advantage of said solution is the measurement of characteristic variables directly at the driveshafts. In turn, a disadvantage is the indirectness of the determination of the torques acting in the driveshafts, as a result of which only a limited degree of accuracy is possible.
DE 103 38 172 B3 describes a wheel-hub/revolute-joint arrangement as is commonly used, in this embodiment or in similar embodiments, for mounting drivable wheels of motor vehicles. In said solutions, a journal on a revolute joint of a driveshaft has an external toothing which engages into an internal toothing of a wheel hub, as a result of which the drive torque can be transmitted. The wheel hub is mounted in the region of the engaging journal in a double-row ball bearing of a wheel carrier. An alternative solution to the wheel bearing is known from DE 36 04 630 C2, in which the transmission of the drive torque from the revolute joint of the driveshaft to the wheel hub takes place via a spur toothing. The wheel hub simultaneously forms the bearing inner ring of the double-row ball bearing for mounting the wheel. For the stated solutions for mounting a wheel which is driven via a revolute joint, no solution is known for determining the torque acting on the wheel.